In Hollywood in the 1940s and ‘50s, a rumor of Communist sympathies was enough to end a person’s career—or at least to force it into an undesired hiatus. The creation of blacklists beginning in the late 1940s left many entertainers barred from performing in certain venues or in TV, radio and film. The Red Channels pamphlet, published on June 22, 1950, served to expand and enhance the existing mechanisms of the blacklists.

The 151 people listed by the right-wing journal Counterattack included actors, authors, musicians and journalists. Some had already been blacklisted, while for others the accusations were new. The fates of those named depended on whether they cooperated with the House Un-American Activities Committee (which many did not) and whether the accusations were ultimately substantiated. Some, like Judy Holliday, endured a period of unemployment before resuming their careers. For others, like actor John Garfield, the list spelled the…